Security readout for executives and security teams
Plain-English summary
CVE-2025-5276 affects mcp-markdownify-server before 1.0.0. A crafted prompt can cause an MCP host to make web requests through Markdownify tools and expose response data. This matters most where MCP servers can reach sensitive services or process untrusted prompts.
Executive priority
Prioritize remediation where MCP tooling is connected to internal networks, secrets, or business systems. For internet-only, constrained deployments, handle as a high-severity dependency update with network egress review.
Technical view
The issue is SSRF, CWE-918, in Markdownify.get(). The affected tools include webpage-to-markdown, bing-search-to-markdown, and youtube-to-markdown. CVSS v4.0 is 8.2 high with network attack vector, low complexity, no privileges, user interaction required, and high confidentiality impact.
Likely exposure
Exposure is likely limited to environments running mcp-markdownify-server versions before 1.0.0, especially where an MCP host can access untrusted prompts and has outbound network access to sensitive resources.
Exploitation context
The source bundle does not show CISA KEV listing or active exploitation. The CVSS vector includes proof-of-concept exploit maturity. Treat this as credible but not confirmed as exploited in the wild based on provided sources.
Researcher notes
The public description points to SSRF through Markdownify.get() and three markdown conversion/search tools. Review the linked fix commit and affected server.ts reference to understand input handling changes. Evidence is incomplete on real-world exploitation.
Mitigation direction
- Upgrade mcp-markdownify-server to version 1.0.0 or later.
- Restrict use of Markdownify tools in untrusted prompt workflows.
- Apply outbound network allowlists for MCP server processes.
- Limit MCP server access to internal or sensitive network destinations.
- Review Snyk and upstream GitHub guidance for implementation details.
Validation and detection
- Inventory MCP hosts using mcp-markdownify-server.
- Confirm installed versions are 1.0.0 or later.
- Identify workflows accepting untrusted prompts into Markdownify tools.
- Review outbound request logs for unusual destinations from MCP hosts.
- Check whether MCP servers can reach internal sensitive services.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-918: Information exposure and cloud metadata lookup
Information exposure and SSRF weaknesses can make discovery, cloud metadata, and credential material review relevant. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupCloud metadata behavior lookup
The CVE wording references SSRF or metadata access, so cloud discovery and credential material review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2025-5276 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- High
- CVSS
- 8.2 (4.0)
- Known Exploited
- No
- Published
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
SSVC decision data
CVSS vector scores
2 official scoresWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P——snykCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N/E:P2.84snykVulnerability scoring details
Base CVSS 4.0 score
8.2HighVector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:N/VA:N/SC:H/SI:N/SA:N/E:P
Base CVSS 3.1 score
7.4HighVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:N/A:N/E:P
Vulnerability timeline
Timeline events are normalized from CVE metadata, CNA source timelines, ADP timelines, and KEV metadata when present.
- CVE reservedCVE Program
The CVE ID was reserved by the assigning CNA.
- CVE publishedCVE Program
The CVE record was published.
- CVE updatedCVE Program
The CVE record metadata indicates this as the latest update time.
ADP provider summaries
Source materials
- CVE List V5 sourceCVE List V5
- https://security.snyk.io/vuln/SNYK-JS-MCPMARKDOWNIFYSERVER-10249387CVE reference, snyk
- https://github.com/zcaceres/markdownify-mcp/commit/0284aa8f34d32c65e20d8cda2d429b7943c9af03CVE reference, snyk
- https://github.com/zcaceres/markdownify-mcp/blob/224cf89f0d58616d2a5522f60f184e8391d1c9e3/src/server.ts%23L20C17-L20C29CVE reference, snyk
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Server-Side Request Forgery (SSRF)
Server-Side Request Forgery (SSRF) represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.